1. Field of the Invention
The invention relates to a recording arrangement including first receiving means for receiving an analog video signal, and including second receiving means for receiving a digital video signal formed by an MPEG transport stream, at least one video packet of a received MPEG transport stream containing video data encoded in accordance with an MPEG video encoding method (MPEG2 standard (video): ISO/IEC DIS 13.818-2), and including video processing means for processing a received video signal and for supplying an MPEG transport stream, and including recording means for recording a digital recording data stream containing an MPEG transport stream supplied by the video processing means.
2. Description of the Related Art
Such a recording arrangement of the type defined in the opening paragraph is known from European Patent Application EP 0671855 A2, corresponding to U.S. Pat. No. 5,548,410, and takes the form of a video recorder. The known video recorder has first receiving means for receiving a PAL or NTSC television signal which includes an analog video signal. Second receiving means receives a digital video signal. Digital video signals can be received as digital video data encoded in accordance with an MPEG video encoding method (MPEG2 Standard (Video): ISO/IEC DIGITAL INFORMATION SIGNAL 13.818-2) in video packets of an MPEG transport stream (MPEG2 Standard (System): ISO/IEC 13.818-1). An MPEG transport stream may comprise encoded digital audio data, associated with encoded video data, in audio packets and additional data in data packets of the MPEG transport stream.
The known video recorder further comprises video processing means for processing a received analog video signal and for supplying analog recording signals to recording means. The recording means records a recording signal supplied in accordance with a VHS or SVHS standard on a magnetic tape of a video cassette.
The video processing means of the known video recorder is further adapted to process a received digital video signal formed by an MPEG transport stream, and to supply a recording data stream containing the received MPEG transport stream to recording means. The recording means is adapted to record a digital recording data stream, supplied in accordance with the digital recording standard, on a magnetic tape of a video cassette.
Thus, the known video recorder records a received analog video signal as an analog recording signal in accordance with an analog recording standard, and records a digital video signal received by the known video recorder as a digital recording data stream in accordance with a digital recording standard.
The known video recorder is found to have the disadvantage that received video signalsxe2x80x94depending on whether they are received as an analog or a digital video signalxe2x80x94are recorded on a magnetic tape of a video cassette in accordance with different recording standards. As a result of this, the recording means of the known video recorder should support different recording standards. A reproducing arrangement for reproducing an analog recording signal or a digital recording data stream recorded on a magnetic tape by means of the known video recorder, should include detection means for the detection of the recording standard of a recorded analog recording signal or digital recording data stream. Furthermore, such a reproducing arrangement should include reproducing means for reproducing the analog recording signal or the digital recording data stream in accordance with different recording standards.
The known video recorder is also found to have the disadvantage that analog video signals received by the first receiving means can only be recorded in an analog fashion and, consequently, the known advantages of a digital recording are not obtained. Such known advantages are, for example, that there is substantially no loss of quality of a video signal during a recording and reproducing process or that even in the case of a recording data stream which is reproduced very frequently from a magnetic tape, hardly any loss of quality can be found.
It is an object of the invention to preclude the afore-mentioned problems and to provide an improved recording arrangement of the type defined in the opening paragraph. In a recording arrangement of the type defined in the opening paragraph this object is achieved in that the video processing means includes video encoding means adapted to encode a digitized video signal, supplied by the first receiving means, in accordance with a further video encoding method (Research Positions on wavelete image processing; Dec. 9, 1996), and to supply encoded video data, and in that the video processing means include insertion means adapted to insert the encoded video data supplied by the video encoding means into at least one data packet of an MPEG transport stream.
This yields the advantage that analog video signals received by the receiving means, as well as received digital video signals contained in an MPEG transport stream, can be recorded as a digital recording data stream in accordance with a recording standard. Consequently, a recording arrangement in accordance with the invention can be particularly simple because it has to support only one recording standard, as a result of which, a particularly cheap recording arrangement is obtained.
The MPEG standard only permits video data encoded in accordance with the MPEG video encoding method to be inserted into video packets of an MPEG transport stream, as a result of which, the requirements imposed by the MPEG standard are met by the insertion of video data encoded by an encoding method other than the MPEG video encoding method into data packets of an MPEG transport stream to be recorded. The compliance with the MPEG standard yields the advantage that video data and audio data of a recording data stream recorded in video packets and audio packets by the recording arrangement can be reproduced by any reproducing arrangement adapted to reproduce a recording data stream recorded in accordance with the respective recording standard and adapted to process an MPEG transport stream.
Moreover, as a result of the advantageous recording of all the received video signals in an MPEG transport stream, a reproducing arrangement can be very simple. Furthermore, it is also possible to record video signals received by the first receiving means as analog video signals, so that the advantages of a digital recording are also obtained for received analog video signals.
It is to be noted that a recording arrangement may include an MPEG video encoder for encoding a digitized video signal supplied by the first receiving means in accordance with the MPEG video encoding method. The MPEG video encoding method is a so-called interframe video encoding method, according to which, a group of consecutive television pictures of an analog video signal are encoded together in a so-called xe2x80x9cgroup of picturesxe2x80x9d. The whole content of a television picture of a group of television pictures is then encoded only once and, for further television pictures of the group, only the changes of these television pictures are encoded, as a result of which, only a small amount of encoded video data must be recorded. However, for processing a group of television pictures, an MPEG video encoder requires memory means with a very high storage capacity, as a result of which, it is practicable only to provide an MPEG video encoder in, for example, a transmitting station and not in a recording arrangement of a video recorder.
In a recording arrangement as described above, it has proven to be advantageous in that the video encoding means for encoding a digitized video signal in accordance with an intraframe video encoding method is adapted to separately encode each television picture of the digitized video signal. This has the advantage that such video encoding means requires memory means having a storage capacity for the storage of only one television picture of a received digitized video signal. This advantageously results in simple video encoding means and, consequently, in a low-cost recording arrangement which can also be used in a video recorder.
In a recording arrangement as described above, it has proven to be advantageous that the recording arrangement further comprises error correction insertion means for generating and inserting interleaved error correction information in accordance with a DVHS standard, and the recording means records a recording data stream in helical recording tracks on a magnetic tape in accordance with the DVHS standard. In accordance with a DVHS standard (Victor Company of Japan, no. 07015 of Jul. 25, 1997), interleaved error correction information generated by error correction insertion means is inserted into DVHS header information of the recording data stream. Here, the interleaving of the error correction information involves a scrambling of packets of a processing data domain including packets of a recording data stream to be recorded in six adjacent helical recording tracks, which data stream may include a multitude of video, audio and data packets. This error correction is referred to as an interleaved error correction. This has the advantage that encoded video data recorded in data packets can be reproduced in a particularly reliable manner by a reproducing arrangement, and that hardly any loss of quality of a received analog video signal occurs in a recording and reproducing arrangement.
In a recording arrangement as described above, it has proven to be advantageous that the first receiving means receives an analog video signal in accordance with the PAL standard, and the insertion means alternately inserts encoded video data of two and of three television pictures of the received video signal into data packets of a recording data stream, said recording data stream being recordable in six helical recording tracks. This has the advantage that PAL-standard television pictures of a received analog video signal can be recorded in a recording data stream on a magnetic tape in such a manner that after the recording data stream has been recorded on a magnetic tape, it is possible to edit encoded video data of television pictures recorded in data packets of the recording data stream.
In a recording arrangement as described above, it has proven to be advantageous that the first receiving means receives an analog video signal in accordance with the NTSC standard, and the insertion means inserts encoded video data of each time three television pictures of the received video signals into data packets of a recording data stream, said recording data stream being recordable in six helical recording tracks. This has the advantage that NTSC-standard television pictures of a received analog video signal can be recorded in a recording data stream on a magnetic tape in such a manner that after the recording data stream has been recorded on a magnetic tape, it is possible to edit television pictures recorded in data packets of the recording data stream.
In a recording arrangement as described above, it has proven to be advantageous that the video encoding means encodes a digitized video signal received by the first receiving means in accordance with a further wavelete video encoding method. This has the advantage that the video encoding means encodes a received digitized video signal in accordance with a known wavelete video encoding method (Research Positions on wavelete image processing; Dec. 9, 1996) and may be formed by a commercially available integrated circuit, so that low-cost video encoding means are obtained.
In a recording arrangement as described above, it has proven to be advantageous that the recording arrangement further comprises control means for insert identification information into a sub-code area of a helical recording track as defined in the DVHS standard when at least one data packet of the recording data stream contains video data encoded in accordance with the further video encoding method. This has the advantage that helical recording tracks containing data packets with encoded video data can be identified and, consequently, it is also possible to record other additional information in data packets.
In a recording arrangement as described above, it has proven to be advantageous that the recording arrangement further comprises a reproducing arrangement for reproducing a recording data stream having been recorded on a magnetic tape as a reproducing data stream, and the control means reads at least one item of identification information contained in the reproducing data stream and having been recorded in a sub-code area of a helical recording track, and the control means supplies control information when identification information is present, and the recording arrangement further comprises video decoding means for decoding video data encoded in accordance with the further video encoding method, and in that the recording arrangement further comprises a demultiplexer for supplying video data contained in the reproducing data stream and encoded in accordance with the further video encoding method to the video decoding means when control information from the control means is available. This has the advantage that received analog video signals, which have been encoded in accordance with a further video encoding method in a recording mode for recording in data packets of an MPEG transport stream, can be decoded in a reproducing mode by means of video decoding means in accordance with a video decoding method corresponding to the further video encoding method.